Expression and function of KCNQ channels in larval zebrafish
Expression and function of KCNQ channels in larval zebrafish
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DOI：
10.1002/dneu.20937
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发表时间：
2012-02-01
影响因子：
3
通讯作者：
Baraban, Scott C.
中科院分区：
文献类型：
--
作者：
Chege, Sally W.;Hortopan, Gabriela A.;Baraban, Scott C.
Kv7家族的成员产生亚阈值钾电流，称为M电流，其调节主要中枢神经元的兴奋性。该家族的两个成员Kv7.2（KCNQ2）和Kv7.3（KCNQ3）的突变与称为良性家族性新生儿惊厥（BFNC）的神经系统疾病有关。尽管它们在正常和病理脑功能中的重要性，但这些通道的发育表达和功能仍然相对未被探索。在这里，我们研究了时间表达的Kv7通道亚基在斑马鱼幼虫使用实时定量PCR方法。利用整体原位杂交技术对斑马鱼脑中的空间表达进行了评估。Kv7家族的三个成员（KCNQ 2、3和5）的mRNA在斑马鱼受精后2至7天（dpf）之间被报道。使用电生理技术，我们表明，Kv7通道（linopirdine和XE991）的抑制剂诱导未成熟的斑马鱼3和7 dpf之间的爆发放电活动。这种异常的电活动被Kv7通道开放剂（瑞替加宾）阻断，并且还显示出在自由游泳的斑马鱼中引起惊厥行为。使用针对KCNQ3的吗啉代寡核苷酸，我们证实了KCNQ通道在产生电突发放电中的作用。这些结果表明，功能性Kv 7通道在幼鱼神经系统中表达，并可能在癫痫发作活动的产生中发挥直接作用。(C)2011 Wiley Periodicals，Inc.开发神经生物学72：186198，2012
Members of the Kv7 family generate a subthreshold potassium current, termed M-current, that regulates the excitability of principal central neurons. Mutations in two members of this family, Kv7.2 (KCNQ2) and Kv7.3 (KCNQ3) are associated with a neurological disorder known as benign familial neonatal convulsion (BFNC). Despite their importance in normal and pathological brain function, developmental expression and function of these channels remains relatively unexplored. Here, we examined the temporal expression of Kv7 channel subunits in zebrafish larvae using a real-time quantitative PCR approach. Spatial expression in the larval zebrafish brain was assessed using whole-mount in situ hybridization. The mRNA for three members of the Kv7 family (KCNQ2, 3 and 5) is reported in zebrafish between two and seven days post-fertilization (dpf). Using electrophysiological techniques, we show that inhibitors of Kv7 channels (linopirdine and XE991) induce burst discharge activity in immature zebrafish between 3 and 7 dpf. This abnormal electrical activity is blocked by a Kv7 channel opener (retigabine) and was also shown to evoke convulsive behaviors in freely swimming zebrafish. Using morpholino oligonucleotides directed against KCNQ3, we confirmed a role for KCNQ channels in generation of electrical burst discharges. These results indicate that functional Kv7 channels are expressed in the larval zebrafish nervous system and could play a direct role in generation of seizure activity. (C) 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 186198, 2012